Well, I don't know much about it -- this is the only time I have ever replaced cabling. But I ordered the Jagwire Mountain Pro, and am really happy with it.
It got so that the rear wouldn't shift reliably. I would clean and lube the cable and it would be great for a ride or two, then act up again. The housings were rusty. Someone here said to replace the cable.
The kit comes with small tubing to cover the cable runs that are not inside housing, with ferrules with "noses" that fit inside the small tubing. There appears to be a pretty thick coating inside the housing -- the center wires are smaller than normal -- and the center wires are covered with Teflon or something. It shifts REALLY smooth and easy.
Stretch is minimal. I adjusted the barrel connector only 1/4 turn on my first ride.
FYI, I replaced the SLX shifters with XT while I was at it, so I haven't done a fair side-by-side comparison.